Turbulence inducer for condensate sub-cooling coil

ABSTRACT

An orifice member for the condenser fan of an air conditioning unit which has a basepan and partition dividing the unit into an indoor section forward or the partition and an outdoor section behind the portion. The wall section has at least one through opening therein laterally spaced from the centerline of the orifice and in close proximity to the basepan. The opening communicates the region of the basepan on the high pressure side of the wall section with the low pressure side region of the basepan, which contains the sub-cooling coil. The opening is located and configured such that when the air conditioner is operating and condensate has collected in the basepan, condensate will be pumped through the opening from the high pressure side to the low pressure side and thereby cause turbulence in the condensate in the region of the basepan which contains the sub-cooling coil.

TECHNICAL FIELD

This invention relates to room air conditioners and is more specificallydirected to the configuration of a condenser coil fan orifice to pumpcollected condensate into the region of a sub-cooling coil located inthe basepan of the air conditioner.

BACKGROUND ART

In air conditioning systems, condensation normally collects on theevaporator coil, runs off and must be disposed of. In room airconditioners, it is common to direct the condensate through variouspassageways to the outdoor section of the air conditioner where thecompressor, condenser coil and condenser fan are located. When the airconditioner has been in operation for some time, a pool of condensatewill collect in the outdoor section of the basepan. Several ways areknown for dealing with the collected condensate in order to improvecondenser capacity and the energy efficiency rating (EER) of the airconditioning unit. One of these is to provide a slinger arrangementassociated with the condenser fan. In a typical slinger arrangement, ablow-through propeller fan coil configuration is used and the condensatecollects at a location where the fan structure causes the condensate tobe splashed onto the condenser coil where it is evaporated thereby,providing cooling to the condenser. Such slingers are typically locatedat the fan blade tips on the discharge (high pressure) side of the fan.

The propeller fan is typically surrounded by a condenser fan shroud,which divides the outdoor section into the previously mentioned highpressure side and the low pressure side, which is on the intake side ofthe condenser fan and in which the fan motor and compressor are located.A second way of utilizing the collected condensate to improve theefficiency of the air conditioning unit is to provide a sub-cooling coilin the basepan of the outdoor section in the low pressure side thereof.When the unit is in operation, this region of the basepan has acollection of condensate therein and the sub-cooling coil is configuredto be at least partially immersed in the condensate, thus, promotingfurther cooling of the liquid refrigerant passing from the condensercoil to the expansion device of the air conditioning unit and thence tothe evaporator coil. Designers of air conditioning units are alwayslooking for additional ways in which to enhance the overall energyefficiency of the unit.

DISCLOSURE OF THE INVENTION

An orifice member for a the condenser fan of an air conditioning unit,which has a basepan and partition dividing the unit into an indoorsection forwardly of the partition and an outdoor section rearwardly ofthe partition. The indoor section includes an evaporator coil, anevaporator fan and means for collecting condensate and directing thecondensate to the basepan in the outdoor section. The outdoor sectionincludes a condenser coil at the rear thereof, a condenser fan having asuction side and a discharge side, which is located forwardly of thecondenser coil, and a compressor. The compressor, condenser andevaporator are connected in a closed refrigeration circuit, whichincludes a refrigerant line between the discharge of the condenser andthe inlet to the evaporator, which includes, serially arranged therein,a sub-cooling coil and an expansion device. The orifice defines abarrier between the suction side and the discharge side of the condenserfan and includes a fan orifice opening therein generally forwardly ofthe fan to define a restricted air flow passage therethrough between thesuction side at a low pressure and the discharge side at a highpressure. The sub-cooling coil is located in the region of the basepanin the outdoor section forwardly of the orifice member and in closeproximity thereto. The region of the basepan in which the sub-coolingcoil is located is configured to collect condensate. The orifice memberhas a wall section underlying the fan orifice opening. The wall sectionhas at least one through opening therein laterally spaced from thecenterline of the orifice and in close proximity to the basepan. Theopening communicates the region of the basepan on the high pressure sideof the wall section with the low pressure side region of the basepan,which contains the sub-cooling coil. The opening is located andconfigured such that when the air conditioner is operating andcondensate has collected in the basepan, condensate will be pumpedthrough the opening from the high pressure side to the low pressure sideand thereby cause turbulence in the condensate in the region of thebasepan, which contains the sub-cooling coil.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be better understood and its objects and advantageswill become apparent to those skilled in the art by reference to theaccompanying drawings, in which:

FIG. 1 is a front perspective view of an air conditioning unit embodyingthe present invention, which has a number of components removedtherefrom;

FIG. 2 is an enlarged view of a portion of FIG. 1;

FIG. 3 is a rear view of condenser fan shroud embodying the presentinvention;

FIG. 4 is an enlarged view of a portion of FIG. 3;

FIG. 5 is an enlarged view of another portion of FIG. 3;

FIG. 6 is a perspective view of the front of the condenser fan shroudillustrated in FIG. 3;

FIG. 7 is an enlarged view of a portion of FIG. 6;

FIG. 8 is a top view of an air conditioner embodying the presentinvention;

FIG. 9 is a view of the air conditioner unit of FIG. 8 taken along theline 9—9 thereof; and

FIG. 10 is an enlarged view of a portion of FIG. 9.

BEST MODE FOR CARRYING OUT THE INVENTION AND INDUSTRIAL APPLICABILITY

In FIGS. 1, 8 and 9, the number 10 generally designates a room airconditioner employing the present invention. As is conventional, theroom air conditioner 10 has a housing 12, which may be located in awindow or through a wall sleeve. The housing 12 is divided by partitionor barrier 14 into an evaporator or inside section and a condenser oroutside section, which are each, in turn, divided into a suction anddischarge section relative to the fans located therein. All of thecomponents of the indoor and outdoor section are supported in astructural basepan 16. The housing 12 includes inlet grille 18, which,when air conditioner 10 is installed, faces the interior of a room to becooled. An evaporator coil 20 is located directly behind inlet grille 18and is mounted within an air directing scroll 22 in which an evaporatorfan 24 is disposed. The fan 24 is driven by motor 28 via shaft 26, whichpasses through and is sealingly supported by the partition 14. Theevaporator fan 24 directs air into the room to be cooled via louvers 19.A condenser coil 30 is located in housing 12 with its discharge sidefacing the outside. A shroud 32 is connected to condenser 30 and theinterior of housing 12 such that a fan chamber 33 containing the movingportion of a condenser fan 34 is formed. A shroud 32 includes an inletorifice 36. Fan 34 is of the axial, shrouded propeller type and islocated entirely in the fan chamber 33 and is connected to motor 28 viashaft 26 such that both of fans 24 and 34 are commonly driven.

It will be noted in FIG. 1 that the shroud 32 is formed from a lowerpiece 35, which is shown in its entirety and an upper piece 37, which isonly partially shown in the drawing figure. The upper part and lowerpart 35, 37 of the shroud each contain a semi-circular opening therein,which cooperates to define the above-described inlet orifice 36 of theshroud 32.

In operation, motor 28 commonly drives evaporator fan 24 and condenserfan 34. Evaporator fan 24 draws air from the room to be cooled with theair serially passing through inlet grille 18, evaporator 20 which causesthe air to be cooled, fan 24 and outlet louvers 19 back into the room.In cooling the air during its passage through evaporator 20, condensatecommonly forms and falls to the lower end thereof where it is collectedand directed in a known manner through the barrier or partition 14 andinto channels 38, which conduct the condensate of the basepan 16 on bothinlet and suction sides of the condenser fan shroud 32. As a result ofsuch flow, condensate collects both in the region 40 rearwardly of thecondenser shroud 32 and in the region 42 forwardly of the condensershroud. Condenser fan 34 draws outside air into the housing 12 via inletopenings 44 in the housing and the air serially passes through the fan34, through the inlet orifice 36, and through condenser 30 rejectingheat from the condenser.

The refrigeration circuit of the room air conditioner 10 includes arefrigerant line 46, which communicates the discharge 48 of thecondenser coil 30 with the inlet 50 of the evaporator 20. Located inthis line 46 is a sub-cooling coil 52, which extends from the condenserdischarge 48 and forms a loop of copper tubing in the basepan forwardlyof the condenser shroud in the region 42 in which condensate iscollected. From the sub-cooling coil refrigerant passes to an expansiondevice 54, which, in turn feeds cooled, condensed liquid refrigerant tothe evaporator, as is conventional.

Accordingly, during operation of the air conditioner, hot liquidrefrigerant passing from the condenser 30 passes through the sub-coolingcoil 52 where its temperature is reduced below the condensingtemperature prior to passing through the expansion device 54 and thenceto the evaporator thereby increasing the efficiency of the airconditioner. The temperature in the sub-cooling coil 52 may be evenfurther reduced when liquid condensate has accumulated in the region 42thus immersing the sub-cooling coil 52 in water.

As best shown in FIGS. 3 through 7, a pair of through openings 56 havebeen provided in the portion 58 of the condenser shroud wall, whichunderlies the inlet orifice 36. It should be noted that each of theopenings 56 is spaced laterally from the centerline 60 of the inletorifice 36. It has been found that by positioning these openingslaterally from the centerline 60 of the orifice by a sufficient distancethat the pressure differential across the condenser shroud 32, asdescribed above, will result in the pumping of air and/or water throughthe orifices 56 in the direction illustrated by the arrows in FIG. 10 tothereby cause turbulence in the condensate collected in the region 42 inwhich the sub-cooling coil 52 is located. Such turbulence has been foundto increase the sub-cooling from approximately four degrees (4°)centigrade up to approximately four and one-half (4.5°) centigrade, anincrease in excess of ten percent (10%).

In the illustrated embodiment, the inlet orifice 36 is approximatelythirty-eight (38) centimeters in diameter and the two openings 56 areeach spaced from the centerline of the inlet orifice 36 by approximatelyfive (5) centimeters to either side of the centerline. Such distancebeing measured from the centerline to the nearest edge of the openings56. It has been found that a centrally located orifice, which is knownin the art, for purposes of allowing condensate flow in the oppositedirection will not produce the same result. It should be appreciatedthat a distance of openings from the centerline of the orifice toachieve the optimum results will vary depending upon the size of the airconditioner and the resulting size of the inlet orifice and the fan, aswell as other variables.

It will be noted that the openings 56 illustrated in the preferredembodiment are substantially elongated having their longest dimensionextending horizontally and parallel to the basepan 16. Each of theopenings illustrates is approximately one and one-sixth (1.6)centimeters long and approximately one-eighth (0.8) centimeters inheight. This ratio of approximately two to one/length to width has beenfound to provide effective flow for inducing the desired turbulence.

While the lateral location of the openings 56 has been shown anddescribed with this preferred embodiment, it has been found that laterallocations ranging from a distance of five percent (5%) to twenty-fivepercent (25%) of the diameter of the inlet orifice will provide pumping,openings located within ten percent (10%) to twenty percent (20%) of theorifice diameter provide closer to optimum pumping/turbulence. It shouldbe noted that in the preferred embodiment the lateral spacing isapproximately thirteen percent (13%) of the inlet orifice diameter.

What is claimed is:
 1. An orifice member for the condenser fan of an airconditioning unit, the air conditioning unit having a basepan, thebasepan having a partition extending vertically therefrom which dividesthe air conditioning unit into an indoor section forwardly of thepartition and an outdoor section rearwardly of the partition, the indoorsection including an evaporator coil, an evaporator fan, and means forcollecting condensate and directing the condensate to the basepan in theoutdoor section, the outdoor section including a condenser coil at therear thereof, a condenser fan having a suction side and a dischargeside, the fan being located forwardly of the condenser coil, and acompressor, the compressor, condenser and evaporator being connected ina closed refrigeration circuit, which includes a refrigerant linebetween the discharge of the condenser coil and the inlet to theevaporator, the refrigerant line having, serially arranged therein, asub-cooling coil and an expansion device, the orifice member defining abarrier between the suction side and the discharge side of the condenserfan and having a fan orifice opening therein generally forwardly of thefan to define a restricted air flow passage therethrough between thesuction side at a low pressure and the discharge side at a highpressure; the sub-cooling coil being located in a region of the basepanin the outdoor section forwardly of the orifice member and in closeproximity thereto, wherein the improvement comprises: said region of thebasepan in which said sub-cooling coil is located is configured tocollect condensate therein; said orifice member having a wall sectionunderlying said fan orifice opening, said fan orifice opening having animaginary vertically extending centerline, said wall section having atleast one through opening therein in close proximity to said basepan andspaced from said centerline by a predetermined distance, said at leastone through opening communicating the region of said basepan on the highpressure discharge side of said wall section with the low pressuresuction side region of said basepan, which contains said sub-coolingcoil; said at least one through opening being configured and saidpredetermined distance being selected, such that, when said airconditioning unit is operating and condensate has collected in saidbasepan, condensate will be pumped through said at least one throughopening from said high pressure side to said low pressure side andthereby cause turbulence in said condensate in the region of saidbasepan, which contains said sub-cooling coil.
 2. The apparatus of claim1 wherein said fan orifice opening is substantially circular and has adiameter, and wherein said predetermined distance is measuredhorizontally from said centerline to the nearest edge of said opening,and wherein said predetermined distance is between five percent (5%) totwenty-five percent (25%) of said diameter.
 3. The apparatus of claim 2wherein said at least one through opening comprises a first opening onone side of said centerline and a second opening on the other side ofsaid centerline, both of said openings being positioned saidpredetermined distance from said centerline.
 4. The apparatus of claim 3wherein said predetermined distance is between ten percent (10%) totwenty percent (20%) of said diameter.
 5. The apparatus of claim 4wherein each of said through openings has an elongated cross-section,with the longest dimension thereof extending substantially parallel tosaid basepan.
 6. The apparatus of claim 5 wherein the ratio between thelongest dimension and the shorter dimension of each of said throughopenings is approximately two to one.